CN110940645A - A portable fluorescence sensing platform and detection method for cadmium ion detection - Google Patents

A portable fluorescence sensing platform and detection method for cadmium ion detection Download PDF

Info

Publication number
CN110940645A
CN110940645A CN201911035710.7A CN201911035710A CN110940645A CN 110940645 A CN110940645 A CN 110940645A CN 201911035710 A CN201911035710 A CN 201911035710A CN 110940645 A CN110940645 A CN 110940645A
Authority
CN
China
Prior art keywords
solution
platform
cadmium ion
fluorescence
portable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201911035710.7A
Other languages
Chinese (zh)
Other versions
CN110940645B (en
Inventor
王平
王心怡
孔留兵
甘颖
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201911035710.7A priority Critical patent/CN110940645B/en
Publication of CN110940645A publication Critical patent/CN110940645A/en
Application granted granted Critical
Publication of CN110940645B publication Critical patent/CN110940645B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64Fluorescence; Phosphorescence
    • G01N21/6402Atomic fluorescence; Laser induced fluorescence
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00Sampling; Preparing specimens for investigation
    • G01N1/28Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/38Diluting, dispersing or mixing samples

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Abstract

The invention discloses a portable fluorescence sensing platform for cadmium ion detection and a detection method. According to the platform, a micro-fluidic chip processed by PDMS is used as a solution cavity, ultraviolet LEDs on two sides excite the solution in the solution cavity, the generated fluorescence is collected by a camera of a smart phone, and finally the fluorescence intensity is determined. The detection method is a method for etching CdTe/CdS core-shell Quantum Dots (QDs) by Ethylene Diamine Tetraacetic Acid (EDTA). Etching of the surface of CdTe/CdS QDs by addition of EDTA to produce specific Cd2+Recognition sites, resulting in fluorescence quenching; when Cd is added2+Thereafter, Cd2+These etch sites can be specifically recognized, resulting in fluorescence recovery. Whereas the recovery efficiency of fluorescence is directly dependent on the added Cd2+Thus the fluorescence intensity reflects Cd2+The concentration and fluorescence intensity of the fluorescent substance can be detected by the portable platform. The invention has the advantages of rapid detection, low detection limit and the like.

Description

Portable fluorescence sensing platform for cadmium ion detection and detection method
Technical Field
The invention relates to the field of cadmium ion detection, in particular to a portable fluorescence sensing platform for cadmium ion detection and a detection method.
Background
Cadmium ion (Cd)2+) Is a heavy metal ion with strong toxicity, is easy to be enriched in various organs of a human body, and has direct influence on the health of the human body. At present, the traditional cadmium ion analysis technology such as atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, electrochemical methods and the like has the limitations of large volume, high cost, complex operation and time consumption, so that the practical application of the cadmium ion analysis technology in field detection is limited. Recently, many researchers have used smartphones as detection elements for various analysis methods because it has not only the advantages of portability and low cost, but also data storage, data processing, and data sharing capabilities. Therefore, the smart phone can be combined with a cadmium ion detection method to form a novel portable cadmium ion fluorescence detection device. Cd combined with smart phone is not available so far2+A fluorescence sensing platform for field measurement and a detection method. Therefore, a simple, rapid, reliable and highly selective portable fluorescence sensing platform and a detection method for trace Cd2+The field test of (1).
Disclosure of Invention
The invention aims to provide a portable fluorescence sensing platform for cadmium ion detection and a detection method aiming at the defects of the prior art.
The purpose of the invention is realized by the following technical scheme: a portable fluorescence sensing platform for cadmium ion detection, the platform comprising: the system comprises a platform shell, a smart phone clamping groove, a smart phone camera, a macro lens, an optical filter, a Micro-fluidic chip, a first stainless steel tube, a second stainless steel tube, a first ultraviolet LED, a second ultraviolet LED, a power supply circuit board, a Micro-USB charging port, a switch, an injection pump, an injector, a waste liquid cylinder and a Micro-fluidic chip clamping groove;
the portable fluorescence sensing platform is provided with a power supply circuit board, and the power supply circuit board is provided with a Micro-USB charging port; a micro-fluidic chip clamping groove is fixed at the bottom of the platform casing and used for placing a micro-fluidic chip, a first ultraviolet LED and a second ultraviolet LED are arranged on two sides of the micro-fluidic chip and are powered by a power supply circuit board, and the opening and closing of the ultraviolet LEDs are controlled by a switch on the side surface of the platform casing; the microfluidic chip is composed of a glass slide and a PDMS-processed cavity, a first stainless steel pipe and a second stainless steel pipe are inserted into two ends of the cavity, the first stainless steel pipe is connected with an injector on the injection pump to control the input of liquid, and the second stainless steel pipe is connected with a waste liquid cylinder to control the output of liquid; a smart phone card slot is arranged above the platform shell, and the smart phone is horizontally placed in the smart phone card slot; a round hole is formed in the top of the platform shell, the round hole is arranged right above the cavity of the microfluidic chip, and a macro lens and an optical filter are sequentially adhered below the round hole; the smart phone camera is arranged right above the round hole, and can be used for collecting images of samples in the cavity processed by PDMS of the microfluidic chip through the round hole.
Furthermore, the power supply circuit board is powered by a lithium battery, the output voltage of the lithium battery is 3.8V, the output voltage of the power supply circuit board is 3.5V, power is supplied to the two ultraviolet LEDs, and the excitation wavelength of the ultraviolet LEDs is 365 nm.
Further, the volume of the PDMS processed cavity was 75 μ L.
Furthermore, the diameter of the circular hole at the top of the platform shell is 10mm, and the diameters of the macro lens and the optical filter are 25 mm. The optical filter is 500nm wavelength pass and can filter ultraviolet exciting light.
Further, the centers of the circular hole at the top of the shell, the macro lens and the optical filter are coaxial.
Furthermore, the power supply circuit board is connected with a green indicator light and a red indicator light, the green indicator light and the red indicator light are exposed outside through an opening in the platform shell, when the battery is charged through the Micro-USB charging port, the green indicator light is on, and when the battery is fully charged, the red indicator light is on.
A cadmium ion fluorescence detection method based on a portable fluorescence sensing platform comprises the following steps:
(1) preparing a cadmium ion detection solution: adding 4740 μ l 10mM Tris-HCl buffer solution with pH 8.5, 660 μ l 100 μ M EDTA and 600 μ l 4 μ M CdTe/CdS quantum dots QDs into a 10mL test tube in sequence, and mixing the solution uniformly; sealing the test tube, and placing the test tube in a dark place to react for 10 minutes at room temperature to obtain an EDTA-CdTe/CdS QDs mixed solution;
(2)Cd2+preparing a standard solution: by introducing Cd at different concentration levels2+Preparing all samples, and obtaining Cd doped with different concentration levels2+The labeled sample of (1); and adjusting the pH value of the spiked sample solution to 8.5 by using 10mM Tris-HCl buffer solution with the pH value of 8.5;
(3) determining an optimal calibration curve for detecting cadmium ions: adding equal volumes of Cd at different concentration levels into 500 μ l of EDTA-CdTe/CdSQDs solution prepared in step (1)2+Adding the solution into a standard solution, fully mixing the solution, and reacting for 20 minutes in a dark place; sequentially pumping the reacted final solution into a disposable injector, and opening a switch on the side surface of the platform shell; placing a disposable injector on an injection pump, wherein the disposable injector is connected to an injection port of the portable fluorescence sensing platform through a connector, and an outlet of the portable fluorescence sensing platform is connected to a waste liquid cylinder; the method comprises the following steps of carrying out image acquisition on each sample through a smart phone, processing each acquired image after all images are acquired, wherein the acquisition and processing process of the sample images comprises the following substeps:
(3.1) opening a camera of the smart phone, setting the camera to be in a professional photographing mode, and setting camera parameters of the smart phone;
and (3.2) starting an injection pump, setting parameters of the injection pump, when the solution is injected into a cavity of a micro-fluidic chip of the portable fluorescence sensing platform, carrying out image acquisition by using a smart phone under the shooting parameters, and continuously acquiring n pictures for each sample at a certain time interval. After image acquisition for each sample was completed. Cleaning with an injector filled with air;
(3.3) after the images of all the samples are collected, processing each collected image; selecting a central area of m pixel points of the cavity part in each photo, selecting a G channel of an RGB channel for analysis, and averaging G values of the m pixel points to obtain a fluorescence intensity value Ig(ii) a Based on the above processing procedure, n images collected from each sample are analyzed to obtain n fluorescence intensities IgValue n fluorescence intensities IgThe values are averaged to obtain
Figure BDA0002251689070000032
A value; obtained by analyzing each sample
Figure BDA0002251689070000033
Value minus control Tris-HCl buffer corresponding to Ig-trisAfter the value, the value I is obtained, i.e.
Figure BDA0002251689070000031
Adding no Cd2 +The value obtained by calculation by using the EDTA-CdTe/CdS QDs solution as a blank group is marked as I0(ii) a Then, the ratio I/I is used0As an index, the concentration of cadmium ion and the ratio I/I are plotted0Curve (c) of (d). Then, fitting a curve algorithm according to a least square method to obtain the concentration of cadmium ions and the ratio I/I0Obtaining the optimal calibration curve of the concentration of cadmium ions according to the linear relation;
(4) detecting the concentration of cadmium ions in an aqueous solution with unknown concentration: regulating the pH value of a solution to be detected with unknown concentration to 8.5 by using a Tris-HCl buffer solution with the pH value of 10mM being 8.5, adding the solution to an EDTA-CdTe/CdS QDs solution, and repeating the steps (1) and (3) to obtain the fluorescence intensity ratio I/I corresponding to the solution to be detected0And (4) substituting the optimal calibration curve for detecting the cadmium ion concentration obtained in the step (3) to calculate the cadmium ion concentration of the sample solution to be detected.
The invention has the beneficial effects that: the invention realizes the on-site rapid monitoring of the concentration of cadmium ions and has the advantages of rapid detection, low detection limit, simple and convenient operation, low cost and the like. Compared with the existing cadmium ion concentration detection method, the method provided by the invention overcomes the defect that the existing method cannot carry out on-site rapid and portable monitoring. According to the advantages, the device and the method can be widely applied to the related fields of environmental monitoring, food safety, heavy metal detection and the like.
Drawings
FIG. 1 is an overall structure diagram of a portable fluorescence sensing platform for cadmium ion detection according to the present invention;
FIG. 2 is a partial block diagram of a microfluidic chip module according to the present invention;
FIG. 3 is a graph of the change in the EDTA concentration versus the CdTe/CdS quantum dot fluorescence ratio of the present invention;
FIG. 4 is a graph showing the results of an optimal calibration curve for cadmium ions determined by the present invention;
FIG. 5 is a flow chart of the method of the present invention;
in the figure, 1, a platform shell, 2, a smart phone, 3, a smart phone clamping groove, 4, a smart phone camera, 5, a macro lens, 6, an optical filter, 7, a Micro-fluidic chip, 8, PDMS, 9, a cavity, 10, a glass slide, 11, a first stainless steel tube, 12, a second stainless steel tube, 13, a first ultraviolet LED, 14, a second ultraviolet LED, 15, a power supply circuit board, 16, a lithium battery, 17, a Micro-USB charging port, 18, a green indicator light, 19, a red indicator light, 20, a switch, 21, an injection pump, 22, an injector, 23, a waste liquid cylinder and 24, the Micro-fluidic chip clamping groove.
Detailed Description
The invention is described in further detail below with reference to the figures and the specific embodiments, but without limiting the invention.
As shown in fig. 1 and 2, the present invention provides a portable fluorescence sensing platform for cadmium ion detection, for portable detection of fluorescence intensity, the platform comprising: the system comprises a platform shell 1, a smart phone 2, a smart phone card slot 3, a smart phone camera 4, a macro lens 5, an optical filter 6, a Micro-fluidic chip 7, PDMS8, a cavity 9, a glass slide 10, a first stainless steel tube 11, a second stainless steel tube 12, a first ultraviolet LED13, a second ultraviolet LED14, a power supply circuit board 15, a lithium battery 16, a Micro-USB charging port 17, a green indicator lamp 18, a red indicator lamp 19, a switch 20, an injection pump 21, an injector 22, a waste liquid cylinder 23 and a Micro-fluidic chip card slot 24; wherein, power supply circuit board 15 is fixed in casing 1 bottom left side, and the Micro-USB on it charges mouthful 17 and exposes outside through the opening on the casing, connects two pilot lamps on the power supply circuit board 15: the green indicator light 18 and the red indicator light 19 are exposed outside through an opening on the shell, when the Micro-USB charging port 17 is used for charging the lithium battery 16, the green indicator light 18 is on, and when the battery is fully charged, the red indicator light 19 is on; a micro-fluidic chip clamping groove 24 is fixed on the right side of the bottom of the machine shell 1, the micro-fluidic chip 7 is placed through the clamping groove 24, two ultraviolet LEDs 13 and 14 are placed on two sides of the micro-fluidic chip 7, the excitation wavelength of the ultraviolet LEDs is 365nm, power is supplied by a power supply circuit board 15, the power supply voltage is 3.5V, and the on and off of the micro-fluidic chip can be controlled through a switch 20 on the side face of the machine shell 1; the microfluidic chip 7 is composed of a glass slide 10 and a cavity 9 processed by PDMS8, the volume of the cavity is about 75 μ L, and PDMS8 is a good light-transmitting material; two stainless steel pipes 11 and 12 are inserted into two ends of the cavity 9, the first stainless steel pipe 11 is connected with an injector 22 on an injection pump 21 to control the input of liquid, and the second stainless steel pipe 12 is connected with a waste liquid cylinder 23 to control the output of liquid; a smart phone card slot 3 is arranged above the shell 1, and a smart phone 2 is horizontally placed in the smart phone card slot 3; the top of the shell is provided with a round hole, the round hole is arranged right above a cavity 9 of the microfluidic chip 7, the lower part of the round hole is sequentially pasted with the macro lens 5 and the optical filter 6, the diameter of the round hole is 10mm, the diameter of the macro lens 5 and the diameter of the optical filter 6 are 25mm, and the centers of the round hole on the top of the shell, the macro lens 5 and the optical filter 6 are coaxial. The macro lens 5 can effectively shorten the imaging distance of the mobile phone and reduce the size of the instrument. The optical filter 6 is a 500nm long-wave pass filter which can filter ultraviolet exciting light; the smart phone camera 4 is right above the round hole, and can collect images of samples in the cavity 9 of the micro-fluidic chip through the round hole.
As shown in fig. 5, a method for cadmium ion fluorescence detection based on a smart phone includes the following steps:
(1) preparing a cadmium ion detection solution: 4740. mu.l of 10mM Tris-HCl (Tris-hydrochloride) buffer solution at pH 8.5, 660. mu.l of 100. mu.M EDTA and 600. mu.l of 4. mu.M CdTe/CdS Quantum Dots (QDs) were added to a 10mL test tube in this order, and the solutions were mixed well. Sealing the test tube, and placing the test tube in a dark place to react for 10 minutes at room temperature to obtain an EDTA-CdTe/CdS QDs mixed solution;
(2)Cd2+preparing a standard solution: by introducing Cd at different concentration levels2+Preparing all samples, and obtaining Cd doped with different concentration levels2+The labeled sample of (1); and adjusting the pH of the solution to 8.5 by using 10mM Tris-HCl buffer solution with the pH of 8.5;
(3) determining an optimal calibration curve for detecting cadmium ions: adding 500 μ l of the prepared EDTA-CdTe/CdS QDs solutionEqual volume of Cd2+Add the standard solution, mix the above solution well, and react for 20 minutes in dark. And (4) sequentially pumping the reacted final solutions into a disposable syringe, and opening a switch on the side surface of the shell. The disposable syringe with the final solution drawn is placed on the syringe pump, the disposable syringe is connected by a connector to the injection port of the portable instrument, and the outlet of the portable instrument is connected to the waste liquid tank. And (4) acquiring images of each sample through the smart phone, and processing each acquired image after all the images are acquired. The acquisition and processing process comprises the following substeps:
(3.1) open the camera of smart mobile phone, set up to professional mode of shooing, the cell-phone parameter setting of making a video recording sets up to: sensitivity ISO is 400, exposure time S is 1.0S;
and (3.2) starting the injection pump, setting the injection speed parameter of the injection pump to be 1000 mu L/min, carrying out image acquisition by using a smart phone under the camera shooting parameter when the solution is injected into the detection cavity of the portable instrument, and continuously acquiring 5 pictures for each sample. Cleaning between every two samples by using an injector filled with air;
(3.3) after the images of all the samples are collected, processing each collected image; selecting a central area of m pixel points of the cavity part in each photo, selecting a G channel of an RGB channel for analysis, and averaging G values of the m pixel points to obtain a fluorescence intensity value Ig
Based on the above process, 5 images obtained from each sample were analyzed to obtain 5 fluorescence intensities IgValue, 5 fluorescence intensities IgThe values are averaged to obtain
Figure BDA0002251689070000051
The value is obtained. Obtained by analyzing each sample
Figure BDA0002251689070000053
Value minus control Tris-HCl buffer corresponding to Ig-trisAfter the value, the value I is obtained, i.e.
Figure BDA0002251689070000052
Figure BDA0002251689070000054
The calculated value of the blank group is recorded as I0(ii) a Then, the ratio I/I is used0As an index, the concentration of cadmium ion and the ratio I/I are plotted0Curve (c) of (d). Then, fitting a curve algorithm according to a least square method to obtain the concentration of cadmium ions and the ratio I/I0Obtaining the optimal calibration curve of the concentration of cadmium ions according to the linear relation;
(4) detecting the concentration of cadmium ions in an aqueous solution with unknown concentration: adjusting the pH value of a solution to be detected with unknown concentration to 8.5 by using a Tris-HCl buffer solution with the pH value of 10mM to 8.5, adding the solution to an EDTA-CdTe/CdS QDs solution, and repeating the steps (1) and (3) to obtain the fluorescence intensity ratio I/I corresponding to the solution to be detected0And (4) substituting the optimal calibration curve for detecting the cadmium ion concentration obtained in the step (3) to calculate the cadmium ion concentration of the sample solution to be detected.
FIG. 3 is a graph of the change in the ratio of EDTA concentration to CdTe/CdS quantum dot fluorescence of the present invention, from which it can be seen that the addition of EDTA causes a significant quenching of the CdTe/CdS QDs fluorescence, leaving it in the off state. As the concentration of EDTA increases, the fluorescence intensity ratio of the CdTe/CdS quantum dots is gradually reduced. This is due to the chemical etching of EDTA, resulting in the generation of CdTe/CdS QDs surface defects and the loss of the surrounding Cd-thiol complex, while fluorescence can be recovered again when cadmium ions are added. The concentration of cadmium ions can thus be detected in this way. FIG. 4 is a graph showing the result of the optimal calibration curve of cadmium ions determined by the present invention, and it can be seen that the cadmium ion detection method based on the portable fluorescence detection platform of the present invention has a good linear correlation with the response of cadmium ion concentration. The optimal calibration curve formula is I/I0=0.0129CCd 2++1.26,I/I0As the ratio of fluorescence intensities, CCd 2+The concentration of cadmium ions in the sample to be detected. Experimental results prove that the method can accurately detect the concentration of cadmium ions in the sample to be detected.
One skilled in the art can readily devise many variations and modifications without departing from the spirit and scope of the invention as defined in the following claims, from the description and drawings. Any modifications and equivalent variations of the above-described embodiments, which are made in accordance with the technical spirit and substance of the present invention, fall within the scope of protection of the present invention as defined in the claims.

Claims (7)

1.一种用于镉离子检测的便携式荧光传感平台,其特征在于,该平台包括:平台机壳、智能手机、智能手机卡槽、智能手机摄像头、微距镜头、光学滤光片、微流控芯片、第一不锈钢管、第二不锈钢管、第一紫外LED、第二紫外LED、供电电路板、Micro-USB充电口、开关、注射泵、注射器、废液缸和微流控芯片卡槽;1. a portable fluorescence sensing platform for cadmium ion detection, is characterized in that, this platform comprises: platform casing, smart phone, smart phone card slot, smart phone camera, macro lens, optical filter, micro Fluid Control Chip, First Stainless Steel Tube, Second Stainless Steel Tube, First UV LED, Second UV LED, Power Supply Circuit Board, Micro-USB Charging Port, Switch, Syringe Pump, Syringe, Waste Tank and Microfluidic Chip Card groove; 所述便携式荧光传感平台具有供电电路板,供电电路板上具有Micro-USB充电口;平台机壳底部固定有微流控芯片卡槽,用于放置微流控芯片,微流控芯片两侧安装第一紫外LED和第二紫外LED,并由供电电路板供电,通过平台机壳侧面的开关控制紫外LED的开与关;微流控芯片由载玻片和PDMS加工的腔体构成,腔体两端插入第一不锈钢管和第二不锈钢管,第一不锈钢管连接注射泵上的注射器控制液体的输入,第二不锈钢管连接废液缸控制液体输出;平台机壳的上方具有智能手机卡槽,智能手机水平放置于智能手机卡槽中;平台机壳顶部上开有圆孔,所述圆孔在微流控芯片的腔体的正上方,圆孔下方依次粘贴微距镜头和光学滤光片;智能手机摄像头在圆孔正上方,通过该圆孔可对微流控芯片的PDMS加工的腔体中的样品进行图像采集。The portable fluorescence sensing platform has a power supply circuit board, and the power supply circuit board has a Micro-USB charging port; a microfluidic chip card slot is fixed at the bottom of the platform case, which is used for placing the microfluidic chip, and the two sides of the microfluidic chip are The first UV LED and the second UV LED are installed, which are powered by the power supply circuit board, and the on and off of the UV LED is controlled by the switch on the side of the platform case; the microfluidic chip is composed of a glass slide and a cavity processed by PDMS. Both ends of the body are inserted into the first stainless steel tube and the second stainless steel tube, the first stainless steel tube is connected to the syringe on the syringe pump to control the input of the liquid, and the second stainless steel tube is connected to the waste liquid tank to control the liquid output; there is a smart phone card above the platform case. The smart phone is placed horizontally in the smart phone card slot; a round hole is opened on the top of the platform case, the round hole is directly above the cavity of the microfluidic chip, and the macro lens and optical filter are pasted under the round hole in turn. Light sheet; the smartphone camera is directly above the circular hole, through which the image of the sample in the PDMS-processed cavity of the microfluidic chip can be collected. 2.根据权利要求1所述的一种用于镉离子检测的便携式荧光传感平台,其特征在于,所述供电电路板由锂电池供电,锂电池输出电压为3.8V,供电电路板的输出电压为3.5V,为两个紫外LED供电,紫外LED的激发波长为365nm。2. A portable fluorescence sensing platform for cadmium ion detection according to claim 1, wherein the power supply circuit board is powered by a lithium battery, the output voltage of the lithium battery is 3.8V, and the output of the power supply circuit board is 3.8V. The voltage is 3.5V to power two UV LEDs with excitation wavelength of 365nm. 3.根据权利要求1所述的一种用于镉离子检测的便携式荧光传感平台,其特征在于,PDMS加工的腔体的体积为75μL。3 . The portable fluorescence sensing platform for cadmium ion detection according to claim 1 , wherein the volume of the cavity processed by PDMS is 75 μL. 4 . 4.根据权利要求1所述的一种用于镉离子检测的便携式荧光传感平台,其特征在于,平台机壳顶部的圆孔直径为10mm,微距镜头和光学滤光片的直径为25mm。光学滤光片为500nm长波通,可以滤除紫外激发光。4. a kind of portable fluorescence sensing platform for cadmium ion detection according to claim 1 is characterized in that, the diameter of the circular hole at the top of the platform case is 10mm, and the diameter of the macro lens and the optical filter is 25mm . The optical filter is 500nm long-pass, which can filter out UV excitation light. 5.根据权利要求1所述的一种用于镉离子检测的便携式荧光传感平台,其特征在于,机壳顶部圆孔、微距镜头和光学滤光片的中心共轴。5 . The portable fluorescence sensing platform for cadmium ion detection according to claim 1 , wherein the centers of the circular hole on the top of the casing, the macro lens and the optical filter are coaxial. 6 . 6.根据权利要求2所述的一种用于镉离子检测的便携式荧光传感平台,其特征在于,所述供电电路板上连接有绿色指示灯和红色指示灯,通过平台机壳上的开口裸露在外,当通过Micro-USB充电口给电池充电时,绿色指示灯亮,当电池充满电时红色指示灯亮。6 . The portable fluorescent sensing platform for cadmium ion detection according to claim 2 , wherein a green indicator light and a red indicator light are connected on the power supply circuit board, through the opening on the platform casing. 7 . Exposed, when the battery is charged through the Micro-USB charging port, the green indicator light is on, and the red indicator light is on when the battery is fully charged. 7.一种基于便携式荧光传感平台的镉离子荧光检测的方法,其特征在于,该方法包括以下步骤:7. A method for cadmium ion fluorescence detection based on a portable fluorescence sensing platform, characterized in that the method comprises the following steps: (1)镉离子检测溶液的配制:将4740μl 10mM pH=8.5的Tris-HCl缓冲溶液,660μl的100μM EDTA和600μl 4μM的CdTe/CdS量子点QDs依次添加到10mL试管中,并将溶液混合均匀;将试管密封,并放置在黑色避光处于室温条件下反应10分钟得到EDTA-CdTe/CdS QDs混合溶液;(1) Preparation of cadmium ion detection solution: add 4740 μl of 10 mM Tris-HCl buffer solution with pH=8.5, 660 μl of 100 μM EDTA and 600 μl of 4 μM CdTe/CdS quantum dot QDs into a 10 mL test tube, and mix the solutions evenly; Seal the test tube and place it in a black dark place to react at room temperature for 10 minutes to obtain a mixed solution of EDTA-CdTe/CdS QDs; (2)Cd2+加标溶液配制:通过引入不同浓度水平的Cd2+制备所有样品,获取掺加不同浓度水平的Cd2+的加标样品;并用10mM pH=8.5的Tris-HCl缓冲液调节加标样品溶液pH=8.5;(2) Preparation of Cd 2+ spiked solution: all samples were prepared by introducing Cd 2+ at different concentration levels, and the spiked samples spiked with Cd 2+ at different concentration levels were obtained; and 10mM pH=8.5 Tris-HCl buffer was used Adjust the pH of the spiked sample solution to 8.5; (3)确定检测镉离子的最佳标定曲线:取500μl步骤(1)中准备好的EDTA-CdTe/CdS QDs溶液加入不同浓度水平等体积的Cd2+加标溶液中,并将上述溶液充分混合,黑色避光反应20分钟;将反应好的最终溶液依次抽取到一次性注射器中,并打开平台机壳侧面的开关;将一次性注射器放到注射泵上,一次性注射器通过接头连接到便携式荧光传感平台的注射口,便携式荧光传感平台的出口连接到废液缸中;通过智能手机对每个样品进行图像采集,采集完所有图像后,对每一幅采集的图像进行处理,样品图像的采集及处理过程包括以下子步骤:(3) Determine the best calibration curve for detecting cadmium ions: take 500 μl of the EDTA-CdTe/CdS QDs solution prepared in step (1) and add it to equal volumes of Cd 2+ standard solution at different concentration levels, and the above solution is fully Mix and react in black for 20 minutes in the dark; draw the final solution after the reaction into a disposable syringe in turn, and turn on the switch on the side of the platform chassis; put the disposable syringe on the syringe pump, and connect the disposable syringe to the portable The injection port of the fluorescence sensing platform and the outlet of the portable fluorescence sensing platform are connected to the waste liquid tank; images are collected for each sample through a smartphone. The image acquisition and processing process includes the following sub-steps: (3.1)打开智能手机的摄像头,设置为专业拍照模式,设置手机摄像参数;(3.1) Turn on the camera of the smartphone, set it to professional camera mode, and set the camera parameters of the phone; (3.2)启动注射泵,设置注射泵参数,当溶液注射进入便携式荧光传感平台的微流控芯片的腔体时,在上述摄像参数下使用智能手机进行图像采集,对于每个样品以一定的时间间隔连续采集n张照片。每个样品的图像采集完成之后。使用装有空气的注射器进行清洗;(3.2) Start the syringe pump and set the parameters of the syringe pump. When the solution is injected into the cavity of the microfluidic chip of the portable fluorescence sensing platform, use a smartphone to collect images under the above camera parameters. N pictures are taken continuously at time intervals. After image acquisition for each sample is complete. Use an air-filled syringe for cleaning; (3.3)采集完所有样品的图像后,对每一幅采集的图像进行处理;具体为选取每张照片中腔体部分m*m个像素点的中心区域,选取RGB通道的G通道进行分析,对m*m个像素点的G值取均值得到荧光强度值Ig;基于上述处理过程,每个样品采集得到的n张图像经过分析,得到n个荧光强度Ig值,将n个荧光光强度Ig值取平均,得到
Figure FDA0002251689060000021
值;将各个样品分析得到的
Figure FDA0002251689060000022
值减去对照组Tris-HCl缓冲液对应的Ig-tris值之后得到值I,即
Figure FDA0002251689060000023
将未加入Cd2+的EDTA-CdTe/CdS QDs溶液作为空白组通过计算得到的值记为I0;再以比值I/I0作为指标,绘出镉离子浓度与比值I/I0的曲线。然后,根据最小二乘法拟合曲线算法,拟合出镉离子浓度与比值I/I0的线性关系,得到镉离子浓度的最佳标定曲线;
(3.3) After collecting the images of all samples, process each collected image; specifically, select the central area of m*m pixels in the cavity part of each photo, and select the G channel of the RGB channel for analysis. The fluorescence intensity value Ig is obtained by averaging the G values of m*m pixel points; based on the above processing process, the n images collected by each sample are analyzed to obtain n fluorescence intensity Ig values, and the n fluorescence intensity values are obtained. The intensity I g values are averaged to obtain
Figure FDA0002251689060000021
value; obtained by analyzing each sample
Figure FDA0002251689060000022
The value I is obtained after subtracting the corresponding Ig-tris value of the Tris-HCl buffer of the control group, namely
Figure FDA0002251689060000023
The value obtained by calculating the EDTA-CdTe/CdS QDs solution without Cd 2+ was recorded as I 0 as a blank group; then the ratio I/I 0 was used as an index to draw the curve of the cadmium ion concentration and the ratio I/I 0 . Then, according to the least squares fitting curve algorithm, the linear relationship between the cadmium ion concentration and the ratio I/I 0 was fitted, and the optimal calibration curve of the cadmium ion concentration was obtained;
(4)检测未知浓度水溶液中的镉离子浓度:将未知浓度的待测样品溶液用10mM pH=8.5的Tris-HCl缓冲液调节溶液pH=8.5后加入到EDTA-CdTe/CdS QDs溶液中,重复步骤(1)-步骤(3),得到该待测样品溶液对应的荧光强度比值I/I0,带入步骤(3)得到的检测镉离子浓度的最佳标定曲线,计算出待测样品溶液的镉离子浓度。(4) Detecting the concentration of cadmium ions in the aqueous solution of unknown concentration: the unknown concentration of the sample solution to be tested is adjusted to pH=8.5 with Tris-HCl buffer of 10mM pH=8.5 and added to the EDTA-CdTe/CdS QDs solution, repeating Step (1)-step (3), obtain the fluorescence intensity ratio I/I 0 corresponding to the sample solution to be tested, bring into the optimal calibration curve for detecting the concentration of cadmium ions obtained in step (3), and calculate the sample solution to be tested cadmium ion concentration.
CN201911035710.7A 2019-10-29 2019-10-29 A portable fluorescence sensing platform and detection method for cadmium ion detection Active CN110940645B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911035710.7A CN110940645B (en) 2019-10-29 2019-10-29 A portable fluorescence sensing platform and detection method for cadmium ion detection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911035710.7A CN110940645B (en) 2019-10-29 2019-10-29 A portable fluorescence sensing platform and detection method for cadmium ion detection

Publications (2)

Publication Number Publication Date
CN110940645A true CN110940645A (en) 2020-03-31
CN110940645B CN110940645B (en) 2021-10-19

Family

ID=69906311

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911035710.7A Active CN110940645B (en) 2019-10-29 2019-10-29 A portable fluorescence sensing platform and detection method for cadmium ion detection

Country Status (1)

Country Link
CN (1) CN110940645B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115161019A (en) * 2022-05-11 2022-10-11 华中农业大学 Preparation method of nitrogen-doped luminescent carbon quantum dots and its application in rapid detection of lysine content in pig serum
CN115711868A (en) * 2022-10-19 2023-02-24 江西省农业科学院农产品质量安全与标准研究所 Fluorescent probe constructed by carbon quantum dots/cadmium telluride fluorescent quantum dots and cadmium ion sensor

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591001A (en) * 2003-08-29 2005-03-09 中国科学院生态环境研究中心 Laser induced fluorescence and light absorption bifunction detecting microflow controlled electrophoresis ehip
KR100819452B1 (en) * 2006-12-07 2008-04-04 이화여자대학교 산학협력단 Microfluidic device including fluorescence chemical sensor and optical measuring method of heavy metal ion using same
CN102331419A (en) * 2011-03-25 2012-01-25 上海汶昌芯片科技有限公司 Heavy metal ion detection chip and preparation method
CN103674902A (en) * 2013-12-12 2014-03-26 中国科学院半导体研究所 LSPR (Localized Surface Plasmon Resonance) portable biochemical detector based on mobile phone platform
CN103901006A (en) * 2014-03-26 2014-07-02 华南师范大学 ZnO quantum dot-based reagent and method for detecting cadmium ions
CN104096602A (en) * 2014-06-03 2014-10-15 青岛博睿林新材料有限公司 Microfluidic chip able to detect cadmium ions
CN104237210A (en) * 2013-06-08 2014-12-24 北京百康芯生物科技有限公司 Portable detection device
CN104777159A (en) * 2015-03-13 2015-07-15 浙江大学 Paralytic shellfish toxin detection method based on image analysis
CN104931440A (en) * 2015-06-12 2015-09-23 中国科学院合肥物质科学研究院 Portable high-sensitivity heavy metal detecting device based on micro-fluidic chip
CN110186880A (en) * 2019-04-18 2019-08-30 浙江大学 The cadmium ion detection kit and its application of CdTe/CdS core-shell quanta dots based on EDTA etching

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591001A (en) * 2003-08-29 2005-03-09 中国科学院生态环境研究中心 Laser induced fluorescence and light absorption bifunction detecting microflow controlled electrophoresis ehip
KR100819452B1 (en) * 2006-12-07 2008-04-04 이화여자대학교 산학협력단 Microfluidic device including fluorescence chemical sensor and optical measuring method of heavy metal ion using same
CN102331419A (en) * 2011-03-25 2012-01-25 上海汶昌芯片科技有限公司 Heavy metal ion detection chip and preparation method
CN104237210A (en) * 2013-06-08 2014-12-24 北京百康芯生物科技有限公司 Portable detection device
CN103674902A (en) * 2013-12-12 2014-03-26 中国科学院半导体研究所 LSPR (Localized Surface Plasmon Resonance) portable biochemical detector based on mobile phone platform
CN103901006A (en) * 2014-03-26 2014-07-02 华南师范大学 ZnO quantum dot-based reagent and method for detecting cadmium ions
CN104096602A (en) * 2014-06-03 2014-10-15 青岛博睿林新材料有限公司 Microfluidic chip able to detect cadmium ions
CN104777159A (en) * 2015-03-13 2015-07-15 浙江大学 Paralytic shellfish toxin detection method based on image analysis
CN104931440A (en) * 2015-06-12 2015-09-23 中国科学院合肥物质科学研究院 Portable high-sensitivity heavy metal detecting device based on micro-fluidic chip
CN110186880A (en) * 2019-04-18 2019-08-30 浙江大学 The cadmium ion detection kit and its application of CdTe/CdS core-shell quanta dots based on EDTA etching

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
FANG LI 等: ""Three-dimensional microfluidic paper-based device for multiplexed colorimetric detection of six metal ions combined with use of a smartphone"", 《ANALYTICAL AND BIOANALYTICAL CHEMISTRY》 *
HAITAO ZHANG 等: ""Selective fluorimetric detection of cadmium in a microfluidic device"", 《MICROCHEMICAL JOURNAL》 *
SI-NAN WANG 等: ""Fluorescence turn-on sensing of trace cadmium ions based on EDTA-etched CdTe@CdS quantum dot"", 《SPECTROCHIMICA ACTA PART A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY》 *
WON-IL LEE 等: ""A smartphone fluorescence imaging-based mobile biosensing system integrated with a passive fluidic control cartridge for minimal user intervention and high accuracy"", 《LAB ON A CHIP》 *
王冠 等: ""基于印迹聚合物的微流控量子点纸基芯片检测环境中的镉、铅离子"", 《分析试验室》 *
王心怡 等: ""基于EDTA 蚀刻的CdTe/CdS量子点荧光探针检测水环境中痕量镉离子"", 《传感技术学报》 *
苟彤: ""基于智能手机的手持式PCR系统开发及其应用研究"", 《中国优秀硕士学位论文全文数据库 基础科学辑》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115161019A (en) * 2022-05-11 2022-10-11 华中农业大学 Preparation method of nitrogen-doped luminescent carbon quantum dots and its application in rapid detection of lysine content in pig serum
CN115711868A (en) * 2022-10-19 2023-02-24 江西省农业科学院农产品质量安全与标准研究所 Fluorescent probe constructed by carbon quantum dots/cadmium telluride fluorescent quantum dots and cadmium ion sensor

Also Published As

Publication number Publication date
CN110940645B (en) 2021-10-19

Similar Documents

Publication Publication Date Title
CN101013087A (en) Method for measuring trace copper ion by using light absorption ratio difference and continuous-flow
CN104764892A (en) Water quality heavy metal multi-parameter online monitoring instrument
CN104655546B (en) A kind of milk somatic cell method of counting and system based on mobile device
CN110940645B (en) A portable fluorescence sensing platform and detection method for cadmium ion detection
CN112461806B (en) Smartphone-based fluorescence spectroscopy detection method
CN104089933B (en) A kind of liquid physical and chemical parameter measurement mechanism based on fluorescence analysis
CN107991275A (en) A kind of optical fiber dissolved oxygen detection method and device based on fluorescent quenching
CN111635931B (en) A multi-target miRNA detection microfluidic chip, detection method and rapid quantitative detection system thereof
CN203949870U (en) A kind of liquid physical and chemical parameter measurement mechanism based on fluorescence analysis
CN110082334A (en) A kind of multichannel optical fiber fluorescent optical sensor
WO2017113545A1 (en) Suck-and-test liquid tester
CN109738622A (en) Rapid detection device for lateral flow paper strips based on microfluidic chip
CN204314225U (en) A kind of food safety fast detecting device based on cell phone platform
CN107748138B (en) Microalgae activity detection device and method based on the principle of filter liquid
CN116625914A (en) A portable counter for raw milk somatic cells and a counting method
CN114166808B (en) Method for Visual Quantitative Detection of Vc Content and Portable Intelligent Sensing System
CN104977334B (en) A kind of experimental provision and method for measuring BOD
CN109406460A (en) A kind of water body Determination of Chlorophyll a content detection device and method
CN204649626U (en) A kind of portable detection equipment based on FRET principle
CN206258378U (en) A kind of light path detecting device of the time resolution detector based on LED cold light sources
CN109959648B (en) Bioluminescence detection device and detection method
CN222087590U (en) Dissolved oxygen analyzer capable of automatic calibration
CN217809435U (en) Integration nucleic acid intellectual detection system equipment
CN115494194B (en) Automatic detection method for pH value of strong acid/alkali solution
CN220643115U (en) A real-time quantitative detection instrument for nucleic acid amplification products

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant